Study Finds Elevated Levels of Toxic Metals in Bloodstream of Regular Cannabis Users
You might want to think again before lighting up that joint.
A new study published in the Environmental Health Perspectives journal outlined some concerning discoveries about regular cannabis users. The team of scientists at Columbia University began their study knowing that cannabis plants can absorb heavy metals from soil, so they sought to find just how much users take in when ingesting cannabis products.
The group looked at blood and urine samples collected between 2005 and 2018 by the National Center for Health Statistics. They found that people who reported using marijuana within the past 30 days had 27 percent higher blood lead levels than those who didn't use either marijuana or tobacco. The cannabis users also had 22 percent higher levels of cadmium in their blood. Urine samples yielded similar results.
These two heavy metals can have detrimental effects on our health. Chronic lead exposure in adults increases the risk of high blood pressure, heart problems, and kidney damage. Cadmium is considered a human carcinogen by the World Health Organization, and exposure to low levels of the metals, such as through tobacco smoke, could lead to kidney disease and fragile bones.
"For both cadmium and lead, these metals are likely to stay in the body for years, long after exposure ends,” study co-author Tiffany Sanchez told NBC News. While the data didn't distinguish between the different ways participants consumed marijuana like edibles or joints, Sanchez emphasized that smoking lead is worse than eating it in food. "The absorption rate from inhalation is 100 percent,” she pointed out.
Related: Marijuana's Other Magic Ingredient
Because marijuana laws across the country differ from state to state, there's no standardized set of rules to regulate contaminants like heavy metals in cannabis products. Of the 38 states where it's legal for either medicinal or recreational purposes, 28 of them regulate arsenic, cadmium, lead, and mercury in marijuana products. This forces manufacturers to test for these metals and ensure the concentrations are below a set limit.
Still, Sanchez noted, "each of the states where cannabis is legal sets their own levels of contaminants." The study did not differentiate between users of legal and illicit cannabis.
Hopefully with the federal government moving to change marijuana's legal status, more research can be done on how to best combat these issues going into a prohibition-free future.
